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Why isn't aircraft structure inspection done by robots? Is there any known active research on the subject?
From my research I've found that (correct me if i am wrong):
Structure inspection (in B,C and D Checks) including (visual, thermography, ultrasonic inspections) looking for structure damage of different type of composit materials (like cracks, dis-bonding, delamination, water ingestion, holes, dents ... etc) in commercial airliners specially wide body aircraft takes alot of time, labor and cost.
So why isn't it done by robots which should be more time efficient, accurate and reliable? in a way that robots can do simple but mandatory inspection tasks allowing operators to focus on more skilled tasks (like engine work) reducing the overall plane down time !
Is there any robotic inspection systems exists that I didn't hear about?
How beneficial to airlines would it be to have a robotic system that would assist operators in the inspection process (in terms of time and cost) ?

I would go further and argue that robots for this kind of work are much less accurate and reliable.  The main problem is with robot vision which is very simple and could not detect anywhere near the range of problems that a trained and experienced human can.

i can agree with you but robots relying on AI and heterogeneous multi agents (using advanced NDI methods like thermography and ultrasonic)can check for faults multiple times in more time efficient way. they can also just inspect in a manner that if they find something suspicious they would report to an operator to check a certain area ... reducing the over all time to inspect the whole structure.
please continue on the discussion :)

You still seem to make assertions with no evidence.  The fact that they are not used is good evidence that your predicate that they are more accurate, more reliable and cheaper than humans is not yet true.

I think your question isn't being well-received because it's rather open-ended and could easily become about opinions. I suggest you re-phrase it to focus on your second question about inspection systems, i.e. ask if any airline is doing it today and/or if there are any active research programs investigating how to do it. Those are much more precise questions that can be answered with examples.

can you please check this link its a system being developed by EasyJet for visual inspection of their aircraft to find visual damage caused by lightning strike. projects like this made me make these assertions :)

Why am I imagining an "airframe Roomba?"

Well, even that system is proposing that human eyes make the assessment.

That takes away jobs by having robots do the inspections. And if the robot is not programmed right it may make a major mistake.

@user11933: Humans get bored.  Robots don't.  Bored inspectors miss things.

The robot, or better the software analyzing the sensor output, needs to be programmed for every eventuality. After all, wear and tear does not leave standard traces, and a human is still better in spotting when something does not look quite right. This does not concern the obvious cases, but those where experience and intuition make the difference.
Next, aircraft structures are made with human inspectors in mind. A robotic system would need to be able to access all points at least as well as a human can. This puts some heavy restrictions on the robot's physique.
Eventually, a robotic system will surpass most humans, but only after thousands of man-hours of training. Maybe someone is developing just such a system right now, but I am unaware of this.
One point remains, however: Who will be liable if the robotic system makes a mistake? The manufacturer will need to buy insurance to cover those corner cases where the robot fails, and this will come on top of the hefty expense for developing and training such a system. I expect that the military (e.g. DARPA) will be the first to make the plunge, and only when the robot has a positive track record will civilian operators start to consider using it.
The EasyJet drones are just helping to get a camera on top of the aircraft; the eventual monitoring of the feed will still be performed by humans. They are a high-tech version of a periscope, if you want.

Are robotic inspection processes used during manufacture?

@TomMcW A key question is the purpose of the inspection. Detect a piece that is not conform to specification is not the same as detecting metal fatigue taht occurs slowly after few flights. Moreover, in the first case, the obvious answer is to throw away the piece, in the second case you may choose either repairs or replacement.

@Manu H Obviously there are many differences between manufacturing inspection and periodic inspection. I'm just wondering if robotic techniques are used during the manufacturing process or if they still have to use manual techniques to ensure accuracy. Many of the technologies will be similar, looking for inconsistencies in material. I'm sure many techniques used for material inspection have been adapted from the manufacturing process

@TomMcW It's possible, but it may be that it's just not cost-effective to make a robot or automated system to inspect a particular part for a particular type, when aircraft are made in such small quantities compared to other things that are made by machine, such as cars.

Thank you, I want to point that the EasyJet drone do inspection on some level, as they use onboard Lidar to generate an accurate 3D model of the aircraft which by use of good analysis software can point to possible damaged , after I saw that project I thought robots can do more than visual inspection. Maybe ultrasonic based on the same concept !


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How did Northrop Grumman propose to make the Global Hawk nuclear powered?
Reading further after receiving this answer, I saw the section on nuclear power in the Wikipedia article on the Northrop Grumman RQ-4 Global Hawk:

Nuclear power
Sandia National Laboratories and Northrop Grumman have studied the possibility of equipping the Global Hawk with a nuclear power plant with US Air Force Research Laboratory funding. A nuclear powered Global Hawk would have a very large range and endurance, and more power for on-board systems. Apart from the technical feasibility, the major drawback however is the fact that drones sometimes crash. So whether this type of propulsion will ever be used on Global Hawk (or any aircraft) is questionable.64, 65

Those references do not give may details on the plan.
Radioisotope thermoelectric generators or RTGs can certainly be compact enough, and generate hundreds of watts or more, but I don't know if they could produce enough power to drive an electric engine.
Was the idea to use electric propulsion, or to somehow generate thrust through direct heating of the air? Or something else?
Nuclear powered aircraft are usually envisioned as quite large, so the proposal to add nuclear power to a Global Hawk may have been substantially different.

@qqjkztd that's better than using a rotating shaft connecting the two and a pair of constant velocity joints; one at the propeller and the other at the motor co-located with the nuclear power plant.

This article explains the technology available for nuclear powered flight Putins Nuclear Power Missile

@jCisco that is an excellent article, thanks! I think the plan for the Global Hawk did not include a conventional reactor based on fissionable material, but instead called for something more unusual.

@uhoh - see the bottom of jCisco's article for a discussion of compact nuclear reactors. Small reactors exist https://www.cna.org/CNA_files/PDF/D0023932.A5.pdf, https://en.wikipedia.org/wiki/High_Flux_Isotope_Reactor. Even in the Pluto/SLAM days, a "conventional" reactor could already power small vehicles like cruise missiles and potentially recon drones. Even Sandia's 2012 paper for a nuclear UAV for Northrop suggests a mature/conventional reactor: https://fas.org/irp/eprint/sand-uav.pdf. I don't think the explanation requires exotic schemes, eg Hafnium nuclear isomers.

You know, if a nuclear UAV didn't want to RTB there's not much the operators could do about it -- it could remain an airborne menace for years.

I didn't find any direct evidence that Northrop Grumman actually proposed a nuclear-powered Global Hawk.
Citation 64 (2 April 2012) in the question doesn't reference a nuclear-powered Global Hawk, only "drones." The pictured Global Hawk was apparently just an illustration.
Citation 65 (August 2003?) in the question does reference a nuclear-powered Global Hawk:

The US Air Force Research Laboratory has funded at least two
  feasibility studies into nuclear powered versions of Global Hawk., [sic]
  which could extend the vehicles flight time from hours to months.

But this August 2003 page (above) appears to be copied from an earlier February 2003 article in New Scientist (below):

The US Air Force Research Laboratory (AFRL) has funded at least two
  feasibility studies on nuclear-powered versions of the
  Northrop-Grumman Global Hawk UAV (pictured). The latest study,
  revealed earlier in February at an aerospace technology conference in
  Albuquerque, New Mexico, concluded that a nuclear engine could extend
  the UAV’s flight time from hours to months.

This is the only reference to a nuclear-powered Global Hawk I've found. I'm not sure this is a reliable source, however, for two reasons. First, this article was published in 2003, just five years after the Global Hawk started flying. That's not a lot of time for AFRL to conduct two feasibility studies for nuclear-powered Global Hawks, though not impossible. I've been unable to find these studies. It's possible these studies were for nuclear-powered ISR drones in general, not the Global Hawk specifically. Second, the New Scientist article references a problematic study by Carl Collins on using a metastable nuclear isomer of Hafnium (Hafnium-178m2) as a gamma/heat source by using xrays to induce the transition/gamma release. The claim has since been discredited (though this may not have been apparent at the time of publication). I'm not saying the author is unreliable (he seems like a decent STEM writer for the MIT Tech Review and Scientific American), but he doesn't seem to have a background in defense or aviation. So there's a possibility he conflated "Global Hawk" with "drone," which wouldn't be unusual of even good journalists then or now.
Northrop's nuclear-powered UAV work seems to predate Global Hawk:

Northrop Grumman is known to have patented a drone equipped with a
  helium-cooled nuclear reactor as long ago as 1986, and has previously
  worked on nuclear projects with the US air force research laboratory.
  Designs for nuclear-powered aircraft are known to go back as far as
  the 1950s. The Guardian

Feasibility of nuclear-powered UAVs
jCisco's arstechnica article gives a surprisingly good overview of nuclear-powered aviation (there's a couple photos I've never seen before). They touch on ANP, the nuclear Bounder hoax, Pluto/SLAM, and Putin's nuclear-powered cruise missiles and torpedoes.
Some discussion of nuclear propulsion: Why don't aircraft use nuclear propulsion?. I'll repeat just one comment I made:

@vsz the water boiler, turbines etc, have to be there and are heavy You
  can actually dispense with the steam turbines entirely. The HTRE
  series were basically modded J47s that sent air through a reactor
  instead of a combustion chamber. HTRE-3 pic. The whole engine+reactor
  assembly is actually lighter than a conventional engine+fuel,
  especially at long range. Rather, it's the shielding that's quite
  heavy. See SLAM/Project Pluto, the Mach 4 nuclear powered ramjet –
  Hephaestus Aetnaean Nov 28 '17 at 17:20

Northrop Grumman (maker of the Global Hawk) did sponsor Sandia to study the feasibility of using 'non-hydrocarbon' fuels for an "ultrapersistent" (read: nuclear) UAV. (Note that even this report doesn't mention the Global Hawk.) 2012 Report summary. Quotes:

Upon completion of the CRADA, Sandia provided a final out-brief to
  NGIS UMS [Northrop Grumman Integrated Systems Unmanned Systems].
  Accomplishments: The effort concentrated on propulsion and power
  technologies that went well beyond existing hydrocarbon technologies.
  It contrasted and compared eight heat sources technologies, three
  power conversion, two dual cycle propulsion system configurations
  [indirect cycle?], and a single electrical power generation scheme [to
  power the ever-hungrier avionics mentioned earlier]. Overall
  performance, specific power parameters, technical complexities,
  security, safety, and other operational features were successfully
  investigated. Large and medium sized UAV systems [probably Global Hawk
  or X-47B and larger] were envisioned and operational flight profiles
  were developed for each concept. Heat source creation and support
  challenges for domestic and expeditionary operations were considered.
  Fundamental cost driver analysis was also performed. System
  development plans were drafted in order to determine where the
  technological and programmatic critical paths lay. NGIS UMS and SNL
  felt that the technical goals for the project were accomplished. NGIS
  UMS was quite pleased with the results of analysis and design although
  it was disappointing to all that the political realities would not
  allow use of the results.

Taking this assessment at face value, nuclear-powered UAVs sound technically feasible.
The powerplant is well understood, suggesting a mature/pre-existing concept (eg a "conventional" nuclear fission reactor) rather than an exotic new concept:

Basic application of the advanced propulsion and power approach is
  well understood

New power/propulsion concepts would probably fall outside the scope of this study, which sounds fairly small and limited to what the sponsor could potentially accomplish in the short/medium term.

Note: "Conventional" is used in the same sense as the OP (I hope): "conventional reactor based on fissionable material." I do not use it here to refer to a specific reactor generation, fuel type, fuel phase, or coolant type.

Thank you for looking into this so thoroughly and taking the time to writing this up. It seems to be fairly clear what happened now. Great answer!

A nuclear powered aircraft was explored in the US, with the Convair NB36H. The idea was to use the heat from the nuclear reactor instead of burning kerosene to run a gas turbine engine. GE actually built a prototype nuclear powered turbine engine, but it was never used in an aircraft.
The NB36H carried a functioning reactor aloft. A lot of shielding had to be added to protect the crew, which added considerably to the weight of the aircraft. Plus, in the event of a crash, the reactor could release a lot of radiation.
The Soviets also experimented with a nuclear powered aircraft, the Tupolev Tu95LAL. It would have used a similar design... a gas turbine that used the reactor heat instead of burning fuel. Like the NB36H, the TU95LAL made many flights with an active reactor on board.
Both projects were abandoned, partially from fear that the thing might crash over their own country with massive radioactive contamination, and partially because the ICBM proved to be a more effective (and less costly) delivery system.
Both the US and USSR also looked into a nuclear powered cruise missile, using a ramjet with nuclear created heat. The radiation trail left behind by this setup in flight was considerable, and both such investigations were terminated.
In the 1950's and 1960's, both nations did things with nuclear technology that, considering what we now know, seem a bit kooky.
I strongly suspect that any attempt to nuclear power a drone will be stopped for environmental reasons (in the event of a crash). A more likely solution to a long distance/long range drone would be aerial refueling via a drone tanker. The US Navy is looking into a stealthy drone tanker, to refuel it's F35's.

Thanks for your answer, but double check my last sentence in the question, and consider how much smaller the Northrop Grumman RQ-4 Global Hawk is compared to a Convair or a Tupolev. I am not sure the technology you are writing about here would be applicable to a small UAV. That's what's motivated this question.

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Is Jetman flying above other aircraft allowed? How it is possible?
According to the Times of India:

Yves Rossy and Vincent Reffet - have achieved the rare feat of flying with the innovative Jetman wings, on either side of an Emirates A380 aircraft, the world's largest passenger aircraft, 4000 feet above sea level.

My Questions are:

Is flying near other aircraft is legal?
How they avoid getting into jet turbulence and other forces?
Is there Jetman suit available to catch up to the jet engined planes?

Here's a related question about formation flying of non-military planes I asked a while ago

Given that this stunt was performed far from the jurisdiction of the US Federal Aviation Administration, I'm not sure why it's tagged "faa-regulations". Are you asking what regulations would cover a similar stunt in US airspace or is the question mis-tagged?

@DavidRicherby So "faa-regulations" won't be applicable, if aircraft flying out of USA jurisdiction?

@Lucky No, of course not. That's exactly what "out of US jurisdiciton" means!

At this low speed, the angle of attack should be high, and air turbulent. I doubt they are close to the plane, The camera angles and lens may provide a false feeling of proximity. Even the two men may not be close to each other to prevent them for being injured by their jet. I would be curious of further details.

Those were your first questions?  My first question was, "How do they land?"

@Michael With a parachute, IIRC.

@Lucky The FAA is the US agency responsible for aviation regulations in the U.S. Other countries have their own similar agencies with their own sets of regulations and jurisdictions. These types of agencies are usually called "civil aviation authorities" or CAAs.

@reirab That was my thought too, but I was struggling to see where it would be fitted... under the wing in the center maybe?  Even then, what happens to the wing and engines, are they disposable or do they have to preserve those for the next flight?

@Michael Sounds like a good question. :)

@reirab - Does the US FAA have "jurisdiction" over a pilot licensed in the US even while that pilot is flying outside of US airspace. In other words, could a US licensed pilot be sanctioned for breaking FAA rules (or some particular FAA rules) while flying outside of US jurisdiction (airspace)? (Perhaps this too should be a a separate question, but it strongly relates to the OP question, and your previous comment).

@KevinFegan How is that related to the question? As far as I know, the pilots were Swiss, French, and Emirati, not American. As far as the jurisdiction of the FAA over American pilots/aircraft outside of U.S. airspace that probably would indeed make one (or two) good questions (which I might already exist... I can't remember.) The short answer, though, is "somewhat" in both cases.

@reirab - Sorry, the context for my comment was related to the faa-regulations tagging of the question, which has now been removed.

Yes.  This is part of a series of promotional stunts, "adverts", Emirates are undertaking.  Aircraft can fly in formation, all other rules taken into account, if the captains agree.
By flying above the aircraft.  As the article states, it was meticulously planned for safety (after all, an accident would be disatrous PR), and the Jetman flyers would know exactly where not to go.
Yes.  The video shows that!  The aircraft will likely be flying at slow speed.  As you can see, the flaps are extended.  I'm guessing about 160 kts.  I would also imagine the flyers will have dived down from above to pick up speed.

They jumped out of a helicopter which, by the looks of the video, was indeed above the flight path of the 380.

To answer the third questions about how they caught up with the A380:

The Jetmen currently fly with a 140 kg high-tech carbon-fiber wing which is fitted with 4 Jetcat P400 engines. The engines are powered by a mix of kerosene and turbine oil capable of pushing a combined thrust of 160kg. This allows us to cover a distance of approximately 40km with speeds of up to 140 – 170 knots.
Source: Jetman Facebook page and Jetman Dubai Facebook page

The A380 approach category is cat (c) the approach speed with flaps should be anything from 121 to 141 knots.

Your second paragraph sounds like a quote from a website or document. If so, please provide a source link.

Its from there facebook page ( jetman Dubai )

A reference is nice, but it's not a link... ;)

@FreeMan - I found these 2 Facebook pages: Jetman Dubai - Facebook, and Jetman - Facebook, but with a quick look, I couldn't find that text.

Based on measurements from https://www.airbus.com/sites/g/files/jlcbta136/files/2021-12/EN-Airbus-A380-Facts-and-Figures-December-2021_0.pdf
The A380's wing span is 79.8 metres tip to tip, and the widest part of the fuselage is about 7 metres so each wing is about 36.4 metres long.
Based on page 4 of https://www.sjsu.edu/ae/docs/project-thesis/Andres.Herrera%20S15.pdf we find a total wingspan of 2.4 metres for the Jetman.

Time to get fuzzy....   The tips of the jet pack don't line up with the A380's wing, so to approximate, I see four of the larger right hand gap and 3 of the smaller left hand gap equalling the wing:

9/7ths of 2.4 metres is about 3.1 metres.   Very approximate but let's see what happens:
Simple division shows that 3.1/36.4 is around 0.85 or 8.5%
Jetman is about 8.5% of the way from the camera to the wing
This triangle can't be solved by Trigonometry because we don't have any angles and only one side, along with the length of a chord/cut and a ratio apart.   Sketching all that results in:

Observations:  Jetman's really small, but that's a very very big aircraft.
Additionally there's a vertical component we haven't accounted for, but the image shows Jetman is well above the vertical stabiliser, perhaps 4x the tails's 15 metre height.  As such it should be well out of the turbulence assuming the plane is straight and level, and Jetman is sliding sideways relative.

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Where can the highest air density be found on Earth?
I would like to see if there is any possibility of testing, validating and actually demonstrating a potential design for drag-mediated rapid braking of an ultralight plane - possibly a solar plane. In reality, a drag coefficient is not really a constant - it varies with both density and speed.
Tests at low density can be done using altitude, but for the highest density points, I am not sure even what densities are ever available anywhere, and how to go about finding these locations.
At first I thought - Death Valley or the Dead Sea area at night, but they can still be fairly warm.
Then I thought the south pole is really cold but then I realized the altitude is quite high.
Then I thought flying over some arctic or antarctic area near sea level would be the highest density, but water can warm the air a bit.
Is there a known place where one could fly through the highest density air on Earth? Is there a world's record? I suppose one could at least analyze historical airport data, but you'd need temperature, pressure and humidity and synthesize a density.
Assume the craft is actually flying and has a pilot on board - no environmental chambers, wind tunnels or mine shafts.

You might try earthscience.SE if you don't get a good answer here; this isn't really an aviation question anyway (in my opinion)

@Pondlife Thanks - I understand.

I'm voting to close this question as off-topic because it belongs on EarthScience.SE

@SMSvonderTann et al. I've made an edit, it may speak to the oh-hold status. It's not always easy to judge how much background information to add to a question. Too much, and the focus of the comments becomes more like 'why would you want to do that?' and 'if I were you I'd...'. Too little and the question looks out of place. I'll try to find a better balance next time. Thanks!

Asking for where air density is highest on earth is still better for Earth Science, regardless of why you want to know. Asking how you could do aerodynamic testing at high/low densities would be better suited here.

@fooot I see what you mean.

My candidate would be Verkhoyansk in Siberia, elevation 140 m. The average temperature in January is only -50°F, so this should be a perfect combination of low and cold to produce density records. They even have an airport conveniently located nearby (ICAO code UEBW), so flying there should only be a minor challenge.
To experience really dense air, you better speed up: Average temperatures are rising there, too. The coldest day ever in Verkhoyansk was recorded in February of 1892 already (-69.8°C).
I could not find a source for actual density measurements, but theoretically those conditions should yield 1.522 kg/m³.

OK got it. So the 'recipe' is low-elevation inland, and as cold as possible. Somehow now Siberia seems so obvious. Compared to a standard atmosphere of 1.225 kg/m³, the drag would be roughly 25% higher there on a cold day. Thanks!

Yep. I should have said drag at a given speed.

@uhoh No, drag would not be higher. You fly slower, so dynamic pressure remains unchanged. But your take-off distance will be much shorter, so the 1200 m runway of UEBW will look like a 1600 m runway under standard atmospheric conditions.

Oh, in reality (real pilot in real plane) of course. I meant with all other parameters held fixed, changing one "knob" at a time, in an abstract sort of way. Thanks for the follow-up!

btw thank you for closing my question (in this case) and pointing me to Earth Science SE. I didn't know about the site, but it's quite helpful. Cheers.

Any place in the arctic near sea level on a cold day would be much lower than the dead sea on a cool day.
Density Altitude Calculator

What about Verkhoyansk or Oymyakon in Yakutia, Siberia, far from great bodies of water? Would you mind to type these places into your calculator? Those places have experienced temperatures down to -90°F in the past.


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What do the radiation patterns of ADS-B transmissions on large airliners tend to look like?
In the recent article Flightradar24 gears up for a new wave of flight tracking I've read about FR24's experimental Wave Glider ADS-B receiver - essentially a self-propelled, solar power buoy as a remote ground station.
What do the radiation patterns of ADS-B transmissions on large airliners tend to look like? In particular, the transmissions that would be received by satellite or surface ADS-B receivers collecting traffic information.
Are there any examples of these radiation patterns published? Are there guidelines, best practices or regulations that apply to the directionality of the radiation?
An example of a general requirement might be EASA's CS-ACNS:

CS-ACNS.D.ELS.060 Antenna installation
(See AMC1 ACNS.ELS.)
(a) The installed antenna(s) has (have) a resulting radiation pattern which is (are) vertically polarised, omnidirectional in the horizontal plane, and has (have) sufficient vertical beam width to ensure proper system operation during normal aircraft manoeuvres.
(b) Antenna(s) is/are located such that the effect on the far field radiation pattern(s) by the aircraft structure are minimised.

which only addresses directions above/below horizontal to the extent that they apply to "normal aircraft maneuvers." There may be more.

Below I've added a similar but different gain pattern as an example of the kind of data I am looking for. However it is the gain pattern for a downwards-looking ADS-B receiving aboard a satellite, showing good reception from below (nadir: $\theta,\phi \approx 0 $). What I am looking for is a similar type plot, but for the radiation from an aircraft.

above: Photo of FR24's ADS-B receiver aboard a Liquid Robotics Wave Glider platform. Photo credit Flightradar24.

above: Example from this paper of an receiver's gain pattern. In this case it is an ADS-B receiving antenna system, aboard a satellite, showing gain optimization looking straight down (nadir).

Are you under the assumption that multiple antennas can't be installed? One on the top of the aircraft for satellite and one on the bottom for ground stations? It may be a purely academic topic though, I know the FAA has been planning a roll-out of ADS-B satellite receivers in the Iridium or GlobalStar constellation, but I don't believe they've launched a single capable satellite as of today.

@RonBeyer Good point! It's a big topic - more than can be covered by a single question. I'm really interested in the overall shape of the pattern and expressed my 'guess' as a reference point only. Do large aircraft often have a "cone of silence" device, and film. Pardon the humor - any helpful information to get me started would be appreciated!

Transport-category aircraft (i.e. airliners) are required by ICAO to have "diverse" 1090ES systems with one antenna pointing up and one pointing down.

@pericynthion That's helpful to know! Is a search for "ICAO diverse 1090ES systems" the best way to try to read further? Do the antennae simply need to appear to point up and down, or is there some requirement on actual RF power delivered in those directions?

It's not clear what you want to understand as there are several illustrative details in your question. It seems from the title that your question could be summarized in "What are the locations and radiation patterns of ADS-B antennas on large airliners? What is the associated regulation, if any?". Note that ADS-B can be used both for air-ground and air-air links (the latter for TCAS messages).

@mins I'll edit to clarify. For this question I am only interested to know if there are general features in the radiation patterns - or even published examples, and if there are guidelines, best practices or regulations on these pattern in any way. I'm only interested in signals that would be received by satellites or surface stations (including buoys).

To start with you may have a look at this draft document from EASA. It specifies draft requirements for "ADS-B out", including antenna requirements (there are vertically polarized and omnidirectional). See page 28: "ADS-B TRANSMIT UNIT". Be prepared to look into other documents referenced here for each aspect. EASA is targeting a mode called 1090ES, that is frequency is 1090 MHz and data rate is "extended" (extended squitter) to support more data to be transmitted (compared to classic mode-S transponders).

@mins OK that's a helpful start - thank you for the link, and for your SE coaching as well!

Also this 1090ES presentation. Someone will come with more information, but this is a good start.

In airliners, like in most aircraft, the ADS-B transmission come from the ATC radar transponder. The transponders in aircraft with an Maximum Takeoff Mass exceeding 5700kg /12500 lbs are required to have antenna diversity. This means that the aircraft will have a top and a bottom antenna connected to the transponder.
ADS-B transmissions are sent out of either the top or bottom antenna, the selection of which should be random with a 50-50 distribution.
Radar and TCAS replies are sent out the antenna on which the incoming interrogation was strongest.
The antennas are vertically polarised and have an approximately omnidirectional radiation pattern in the horizontal plane. In the vertical plane, most radiation energy will be focused 45 degrees around the horizon. They have a cone of silence.
The aircraft structure blocks and reflects part of the radiated energy. This is causing the far field pattern to be not uniform and varies from aircraft to aircraft. On the lower antenna the main effect is of the fuselage and the engines. On the top antenna the fuselage, the tail and the wings/winglets are the main obstacles.
On small aircraft this is more of a problem, especially when the transponder antenna is between large fixed gear struts.
This study contains an antenna pattern of the top antenna of an aircraft

Thanks! This is a very helpful description of the general pattern, and about the handling of the top and bottom antennas. I see you reviewed my comments carefully - I have just now found out that "cone of silence" is an actual aviation term for this. I'd thought it was a remarkable coincidence that it suited the situation so well

You're welcome. This is very closely related to work I did. I worked with the people who wrote the documents @mins linked to. Establishing the exact radiation pattern of aircraft is not easy. I have tried to do this from received signal power in terrestrial ADS-B receivers but it is not straightforward to distinguish effects of signal multipath, receiver antenna pattern and aircraft antenna diversity.

If received signal strength were recorded and logged as standard, and could be accumulated, over time one could build a sort-of "reception cloud" of data around an aircraft. It it had a dead spot, over an extended period of time and variety of routes the dead spot would start to show up if one data-mined extensively. It's not a proper measurement of course, but it could be interesting. I don't know if received signal strength is really accessible for such a large volume of data required.


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I'm so confused how airport numbering works
I'm so confused how airport numbering works.  If an airport has a single runway oriented 063 degrees and 243 degrees M.  What would be the runway designator?

06/24... what is the confusing part? Rounding?

I know that runways are determined by their heading so runway 243 is like  South West and 063 would be North East.

Right, so I'm wondering what the confusing part is, how the numbers are rounded? Runways aren't identified by cardinal points (NE, NW, SW, etc).

I'm confused myself because its one of the questions on this textbook that im studying and it says the following.  "An Airport has a single runway oriented 063 degrees/243 degrees M.  What is the appropriate runway designato?"  So what i dont get is how runways are designated or i guess identified.

06/24 like I said, runways are designated by the first two digits of the 3-digit magnetic heading. 025 = 02, 122 = 12, etc. Take a look at the duplicate question I marked.

When a runway is at Magnetic Heading 063, it is rounded to the nearest 10° , which is 60°, so its designation is Runway 06
When a runway is at Magnetic Heading 243, it is rounded to the nearest 10° , which is 240°, so its designation is Runway 24
Since you can take off or land on a runway from either end, a single strip of asphalt will typically have two numbers, one for each end.  These two numbers will always be 180° apart, or their designations will be 18 different.
So Runway 06/24 refers to a single runway, that you can use from either end.


text:
Can variable incidence wings replace ailerons?
If a wing can change its incidence angle, can aileron be omitted in the design?
Since aileron are used to increase lift and decrease it. so is the incidence angle.
How would the two solutions compare?

If each half of the wing is independent, it can be used to control the roll angle. Is it efficient? Not as efficient as ailerons. Ailerons create the required roll moment with a minimum of additional drag by changing the wing camber only near the wing tips, taking advantage of the distance to the roll axis. A variable incidence wing would change the angle of attack everywhere, including near the wing root, a location where the lift has little contribution to the roll moment, but normal contribution to induced drag.

This should be the accepted answer.

Ailerons were reinvented as a way around the Wright patent on wing warping. So yes, it can!

In principle, yes.
But, what would be the result of it?
Modern aircraft wings are a result of sophisticated design. They could consist of the following parts: Flaps, slats, spoilers, pylons, fuel tanks, winglets (of course the ailerons) and some also hold the engines. If the entire wing is to be moved, all of these parts would need to be moved too, or else, engineers will have to come up with a complex design that could keep some of them stationary. Each of these parts have their own function. Would they operate the same way if the wings moved? Maybe not.
Moreover, the amount of aileron deflection required to create a change in drag at a higher altitude is much lower than that required at a lower altitude for the same amount of drag. Such fine control is hard to achieve if the entire wing is moved.

So did the Wrights in their 'Flyer'. It had no ailerons, but the wings could be slightly deformed to roll the plane.
Possibly for constructive reasons, ailerons are almost always used today for roll control (spoilers are sometimes used in very light planes) but the Wrights' method was more elegant...

The B-52 uses spoilerons. See wiki article.

Some radio control gliders use wings that can change pitch angle independently. "Wingeron" models, use the wings for roll control, but have a conventional elevator. "Pitcheron" models use the wings for pitch and roll control and have a fixed horizontal stabilizer instead of an elevator. A "computer" transmitter is used on "pitcheron" models to mix roll and pitch control inputs into servo position output commands (also used to reduce or eliminate any adverse yaw issues). These type of models tend to be aerobatic oriented, and weigh more than conventional model gliders, as the lighter models would have a smaller sink rate.


text:
What is the proper air strip closure procedure with the FAA?
I own a grass airstrip that was registered for me by a good friend.  I want to sell my land and the guy that registered it is dying and can't help me.  What do I need to do to have this airstrip closed?

For what it's worth, the usual way in my part of the country (Oregon) for land owners to physically inform pilots that an airstrip is closed is to use plastic sheeting to form a big X's on the ground. The FAA document at http://www.faa.gov/documentlibrary/media/advisory_circular/150_5340_1k_consolidated.pdf in section 5.6 gives detail and a graphic in figure 25 near the very end.

It looks to me like you need to file FAA Form 7480-1, Notice of Landing Area Proposal.  There is a checkbox for "Deactivation or Abandonment".
The form explains that you have to give 90 days advance notice.  So you shouldn't make any changes until 90 days after filing the form.  This presumably gives them time to update charts, so that pilots know the airstrip is no longer usable.
The form has the address and phone number for your FAA regional office, who might be able to help if you have questions about how to complete the form.


text:
How is flow separation related to the chord length of an airfoil?
I came across this question while studying stalling of airfoils. How does the chord length of an airfoil affect the position of the separation point of flow?
https://en.wikipedia.org/wiki/Flow_separation
The Wikipedia article on flow separation isn't very clear on what is the relation between location of separation point and Reynolds Number (and thus Chord Length).

Could you please link to the question? Without a link it is hard to know what you refer to. If you are unsure about linking: Click on edit, highlight the text and then call up the link dialog by clicking on the chain symbol on the bar above the edit box. Enter the link there and save.

@JayMetha, it appears you edited the question, but didn't do it from the same account or browser, so the edit needs to be approved. Please, try to consolidate your identity (I am sure it is described somewhere in help).

@JanHudec I submitted the question as a new user on my browser and edited on the iOS application. I'll post the question again with the edit as I can't find a solution to the problem

@JayMehta, absolutely don't post the question again.

The chord length is a minor influence. The main driver for separation is the local pressure gradient.
Make sure to read the first three paragraphs of this answer if you are unsure how the pressure gradient drives separation.
The chord length only comes into play via the local Reynolds number. Higher Reynolds numbers mean steeper pressure gradients can be tolerated, but the effect is rather weak. It shows in the separation point which moves back slightly on the upper side of an airfoil near stall at the same angle of attack when the Reynolds number is increased.


text:
Why do modern aircraft have a slope on top of the airfoil?
I recently learned that the pressure on the bottom of the wing is increased, and air moves faster on the bottom part of the wing. The speed of the air on top of the wing is not increased. So I am confused about what is the point of the slope on top of the airfoil. The Wright brothers' airfoil was flat, but still had the slight slope to it, and now modern aircraft have a huge slope to them. So what is the reason for the slope?

Hi Ethan.  You should know by now that this is not how wings work.  You have taken part in enough Q&As on here to know that, for example, this one.

To understand how a wing maintains the aircraft airborne, in addition of the multiple answers you have got on this site, you may read the full explanation here. In particular you should first understand this image: The same wing, on the top it doesn't produce lift, on the bottom it produces lift because air is deflected downward by the wing. Read it until you understand most of it, as other details are then explained from the assumption you understand this important basis.

First of all, wherever you learned that, "...the pressure on the bottom of the wing is increased, and air moves faster on the bottom part of the wing. The speed of the air on top of the wing is not increased." It is wrong, and citations would be useful, if only to educate the owner of that website.A wing provides lift by imparting momentum to the air through which it passes equal to the airplane's weight. If the wing is cambered, it imparts more acceleration to the air through which it passes. (i.e. the air coming off the trailing edge has a faster downward velocity than compared to a non-cambered airfoil of equal area), thus making the wing more efficient for its area. It also affects things like stall speed.

" imparting momentum to the air through which it passes equal to the airplane's weight" That's not possible. The units of momentum are mass-times-velocity and the units of weight are mass-times-acceleration.

The slope (known as the camber) is for better stalling characteristics so that the turbulent flow separates from the airfoil slowly instead of suddenly because the curve allows the air more surface to stick on at the AoA increases to a stall.
This stall diagram shows how the cambered wing performs in a stall:

Image Source
Also, according to the gas laws, the air in higher pressure moves slower than air in low pressure. (P1*V1 = P2*V2) The air on the upper surface does move faster at higher AoAs due to the lower pressure created by the AoA.

You are wrong about the air under the wing travelling faster. It is the air travelling over the top of the wing that is faster.
The "slope" is actually called Camber. Camber makes the air flowing over the wing change direction and this causes low pressure and that results in lift.

There is no reason why the air flowing over the top of the wing has to "join up" with the air that passed under it. In fact, the airflow over the top gets to the trailing edge before the air going under the wing. Please see http://www.av8n.com/how/htm/airfoils.html#sec-airplane-air.

The theory of equal transit time has been busted for quite some time. https://en.wikipedia.org/wiki/Lift_(force)#False_explanation_based_on_equal_transit-time

@Simon True but it is still widely taught and even appears in some countries syllabi IIRC. It's a very common misconception that sparked the question in the first place and an answer like this one would be good if it explained such.

Nasa says: This is an incorrect theory.

Also, the aerofoil in the diagram doesn't actually seem to be generating any lift since there's no reaction on the air mass.

I edited my answer to remove the "join up" statement.


text:
How does the dihedral angle work?
I've been looking for this topic on the internet but I don't have enough concrete answers. Suppose we have a plane with dihedral and it has a suddenly swinging to the right (watching from the nose of the plane), so the right wing goes down. I'm trying to understand why the right wing generates more lift than the left wing when it has a sideslip. I have seen in some sites that the sideslip induces a flow from the tip to the root and this makes the right wing increase locally the angle of attack, hence the lift of this wing increases too.
But, why the right wing increases the angle of attack? I think it couldn't be possible because the sideslip flow is in a different plane respect the mainstream.

start from here

To me this is not a duplicate. We have no question on the site explaining the principle behind anhedral/dihedral. I concede, though, that some rewording might be required.

sorry, my native language is not English, so I know I have a lot of mistakes. Anyway, I know "watching from the nose" is not very clear. What I meant is " seen in the same direction that leads the mainstream "

Basically, dihedral effect is that during banking, the 'lower' wing will experience a higher angle of attack compared to the 'higher' wing, and a result, a greater lift. The resulting net force and moment reduces the banking angle, reducing stability.
Consider a wing with a dihedral angle $\Gamma$ with a forward airspeed of $u$. If the sideslip angle is $\beta$, the wind due to sideslip is $u \cdot \sin\beta$. From geometry, the normal velocity induced due to dihedral, $v_{n}$ becomes $u \cdot \sin\beta \cdot \sin\Gamma$.

Image from Stability and Control of Aerospace Vehicles
Note: The notations are different in the figure; but the principle is the same.
For our purposes, we can take the sideslip velocity ($u \cdot \sin\beta$) as $v_{y}$. Now, consider two sections from the wing - one each from the 'lower' and 'higher' sides. The induced velocity is of the same magnitude in both the sides, while the direction differs, as can be seen from the above figure.

Image from people.rit.edu

Image from Stability and Control of Aerospace Vehicles
For small angles, $v_{y}$ is nearly equal to $u \beta$. The induced angle can be given as,
$\Delta \alpha = \frac{v_{n}}{u}$.
From the earlier relations, we have,
$\Delta \alpha_{1} = \beta \cdot \sin\Gamma$, and $\Delta \alpha_{2} = -\beta \cdot \sin\Gamma$.
Because of these induced angles, the lift on the downgoing wing increases by $\Delta L$, while of the other one decreases by $\Delta L$. The net result is that the 'lower' wing experiences an increases lift, causing a rolling moment, which causes the banking angle to reduce.

Image from Stability and Control of Aerospace Vehicles

The can of worms that has not yet been opened in this answer, is "what causes the sideslip?"

The explanation lies in the fact that a rolled wing creates a oblique relative wind, and that a wing with a dihedral angle seen from an oblique direction is having a larger angle of attack on the side in this direction:

Because of the dihedral angle, for the wind coming from an oblique direction on the right of the aircraft, the right wing shows a larger AoA. This is even more important for a larger dihedral angle.
Visual demonstration
On the image below:

On the left side, there is an aircraft which is horizontal, flying level, and in a relative headwind. Obviously the action of the wind will be the same on both wings, whatever the dihedral angle, and the lift vector is oriented vertically (in blue).
On the right side, the aircraft has been disturbed and for some reason is now rolled to the right without pilot action. Imagine the heading is still the same.

The key to see what will happen is to understand the right wing now develops more lift than the left wing, the difference being proportional to the dihedral angle. As soon as this is clear, we can anticipate the roll angle will be cancelled automatically, without pilot action.
Let's look at the rolled aircraft:

The lift vector, which is still normal to the wing, is no more vertical. From a mathematical point of view it can be split into two components along arbitrary directions. If we choose a resolution along the vertical and horizontal axes, we see the vertical component is now smaller (therefore the aircraft starts descending) and a horizontal component appeared in the process.
The horizontal component pulls the aircraft to the right side. As the heading is unchanged, the aircraft is not in a turn, and no centrifugal force opposes this horizontal component of the lift, therefore the aircraft starts side-slipping and the relative wind is no more a headwind, there is some crosswind from the right side.

Angle of attack seen from the relative wind standpoint:

When the aircraft was flying in a headwind, the angle of attack was the same for both wings.
With the crosswind component, the angle of attack of the right wing is higher than the angle of attack of the left wing. The difference is small when the dihedral angle is small, and increases with its value. To make this apparent, I added wings with higher dihedral angles to the aircraft:

Note: The difference appears only when the wind is off axis. This means the dihedral effect on the angle of attack exists only when there is a sideslip.
Of course because the angle of attack is larger on the right, a recovery moment starts developing and counteracts the initial roll. The aircraft returns to the horizontal after some damped oscillations around the longitudinal axis.
The lateral stability is of prime importance for general and commercial aviation aircraft. The dihedral angle is the most simple mean to obtain this stability, there are others.
Stability from swept wing, due to spanwise flow
Lift is generated taking into account the airflow parallel to the chord which is accelerated. Air moved in a perpendicular direction is not accelerated and doesn't create any lift, see left image:

(By principle, a swept wing decreases the amount of lift created, this is compensated by other benefits that make it useful anyway).
If the swept wing receives wind from an oblique direction, like during a sideslip, the available air energy will not be lost in the same proportion for each wing (see image on the right, above).
The chord of the right wing is better oriented in the airflow coming from the right, and a larger ratio of air generates lift compared to when the airflow comes frontally. This is the contrary for the left wing. This effect also contributes to lateral stability.
Preventing spiral
The dihedral angle participates to the roll stability, along with other factors. The area where the dihedral plays a critical role is the stabilization of the spiral mode (or spiral divergence).
The spiral mode, like the Dutch roll and the phugoid, is an oscillatory mode that can either self-decay with time (stable) or constantly increase (unstable). The unstable spiral mode happens this way:

(1) The disturbance creates a small roll moment and sideslip to the right.
(2) The sideslip creates a crosswind component from the right.
(3) The vertical stabilizer AoA increases and creates lift to the left.

(4) Lift creates a yaw moment and turns the nose to the right.
(1) The yaw moment increases the roll moment and the sideslip to the right (a new cycle has begun).

If this effect is not detected and corrected, which can easily happen in IMC when the natural horizon is not visible, the aircraft continues to sideslip and yaw, while the vertical component of the lift decreases due to the roll, creating a dangerous spiral downwards which can lead to structural damages or ground collision.
The cycle is the result of all dynamic forces in action on the aircraft, in particular the lift on each wing and the position of the center of pressure.
The use of a dihedral wings affects the forces and their relative timing, and transforms an unstable spiral mode into a stable one. This is facilitated by also using a smaller vertical stabilizer and rudder, which in turn can create an unstable Dutch roll, or a shorter cabin.

Thanks to ahmetsalih for the Learjet 3D model available at TF3DM.

You've got me really confused. The disturbance creates the small sideslip to the right. but The sideslip creates a crosswind component from the right. This seems backwards. If you yaw right the crosswind would be from the left side.

When you say sideslip to the right do you mean the tail goes to the right or the nose?

My brain is hurting! If the nose turns to the right wouldn't the crosswind component be from the left side?

Plus, I thought a roll caused an adverse yaw

@TomMcW: The aircraft sideslips to the right ⟹ the aircraft now moves to the right ⟹ a relative crosswind from the right ⟹ the tail creates a nose yaw to the right. For the adverse yaw, yes but is cancelled by the crosswind on the tail. I added a picture for this effect. Remember this is a mechanism without dihedral, the dihedral being the solution to the unstable spiral.

Ok, still one thing I'm not straight on. (Sorry to keep picking. I've been trying to understand roll stability for a long time) Your final bullet point says The yaw moment increases the sideslip. Isn't the yaw to the right due to weathervaning, therefore decreasing the slip? It would make sense if you said " "The yaw moment increases the roll" which starts the whole chain over again.

Excellent answer, mins, helped me understand quite a bit better. --  What boggles my mind is how the Wrights and other early aviation pioneers managed to sort all these things out to make working aircraft without really understanding what they were facing.

I'm sorry to nitpick an old answer, but the phrase "The spiral mode, like the Dutch roll and the phugoid, is an oscillatory mode " sounds wrong to me. The phugoid (long period) mode and the Dutch roll both have complex eigenvalues associated with them, which imply an oscillating mode (which may converge or diverge), while the spiral divergence and roll subsidience have real eigenvalues, which do not lead to oscillation. Not to say there can't be coupling or the spiral mode may not excite others, but it is not inherently an oscillatory mode.

@AEhere: Yes it would be more correct to call the rolling and spiral modes exponential modes. Good comment.

Glad you found it useful. Also, that's the same pdf I throw at people! Helped me a lot in uni to counterbalance the theory heavy / application scarce approach of our recommended bibliography.

@quietflyer: "You can't explain the cause of the sideslip just by splitting the lift vector". I don't understand what you mean, the cause of the sideslip is the horizontal component created by the roll. See this explanation of Wikipedia: "In the sideslip condition, the airplane's longitudinal axis remains parallel to the original flightpath, but the airplane no longer flies along that track. The horizontal component of lift is directed toward the low wing, drawing the airplane sideways". I didn't say anything else.

My comment should better have read, "You can't explain the cause of the sideslip just by noting that the net lift vector contains a horizontal component when the aircraft is banked."  After all, isn't the same true  in any normal "coordinated" turn?  What is the particular thing about an uncommanded bank that makes it cause a sideslip as well as (presumably) a turn?

More along these lines:  a steady horizontal force component acting perpendicular to the flight path creates a curvature in the flight path, not a sideslip.  Example: the wires on a control-line model airplane.  A flat turn, no slip.  But in the case you are discussing, the net force from the wing should be perpendicular to the wingspan just like in any normal coordinated turn, unless some particular thing is acting to move the aircraft sideways through the air in a sideslip.  So what is that thing?

@quietflyer: "You can't explain the cause of the sideslip just by noting that the net lift vector contains a horizontal component when the aircraft is banked. After all, isn't the same true in any normal coordinated turn?". Yes in a coordinated turn there is the same horizontal lift component. However as the aircraft is now turning, this force is balanced by the centrifugal force and there is no sideslip. See also this.

Re above: a) so why is the aircraft not turning in the case of the uncommanded bank, just as it is in the case of the pilot-commanded bank?   Or perhaps, it IS turning in both cases?   b)  re "see 'this'"-- not a very helpful diagram.  "Centrifugal force" is not a real force and only can be included if we use the aircraft itself as our reference frame, rather than the earth.  The aircraft is not a valid inertial reference frame, while the earth is.  The diagram fails to include the actual aerodynamic cause of the different forces experienced in a skip versus a skid versus a coordinated turn.

The diagram fails to reveal that the key difference between a "coordinated" and an "uncoordinated" turn is that in the former case, the nose of the aircraft is pointing in the same direction as the aircraft is actually moving through the air, and in the latter case, it is not, so the airflow strikes the side of the fuselage and creates an aerodynamic sideforce. So, bearing that in mind, why is an uncommanded bank and turn inherently "uncoordinated"- inherently involves a sideways component in the airflow over the aircraft- if the same is not also true of a bank and turn commanded by the pilot?

@quietflyer: "So, bearing that in mind, why is an uncommanded bank and turn inherently "uncoordinated"- inherently involves a sideways component in the airflow over the aircraft- if the same is not also true of a bank and turn commanded by the pilot?". You're using the comments as a chat, I can't follow you in that direction, this is my last answer to your questions: I think the answer is pretty clear about the relative wind, and how it compares or not to a coordinated or uncoordinated turn: The disturbance doesn't create a turn, doesn't change the heading, it just rolls the wing.

Re last sentence- why?  Why would the aircraft not turn, once it is banked?

Coming to the aid of the -5 @rbp answer, having been there, and a few items to improve the answer, and to respond to the question "how does dihedral work", as follows:
What is missing in our exaggerated 45 degree model is an evaluation of total lift, vertical lift, and center of lift relative to center of gravity.
One of the quirks of physics is that a 45 degree angled wing still produces 70.7% vertical lift of a zero degree angled wing (relative to the earths surface).  This means that both wings at 45 degrees produce 42% more vertical lift than one wing at zero degrees and one at 90 degrees.
What happens when the plane rolls?  Vertical lift is lower and the plane SINKS.  The aircraft now has a vertical direction component, there for a change in "relative wind".
Now, where is the roll torquing force around the center of gravity coming from?  Many have correctly stated that it can not be from the lift vectors, and many have correctly stated it comes from the "slip".
Notice what effect a VERTICAL component will have on the wings.  Obviously the zero degree wing will be rolled up from the relative wind (vertical component) until its angle is equal to the opposite wing, restoring the original attitude and lift condition.
The side force, created by the 90 degree wing, also adds side motion.  The net motion of the plane is a slip down and to the side until the wings re-level.  That's the aerodynamic part, but that's not all!
When the plane rolls, the center of vertical lift, relative to the center of gravity, moves out of alignment, creating a "yin and yang" roll torque effect which also helps right the aircraft.
Dihedral is present in many aircraft designs where cruising comfort is preferred and flight other than straight and level is uncommon.

Note: a rolling plane will have a difference in AOA between the ascending and descending wing ("roll subsidence") as explained by @aeroalias, but the roll must stop, then reverse, to return to wings level.

I'm having a little trouble fully understanding your answer.  Imagine we are in a 60-degree banked turn maintaining constant altitude, and then we shove the stick or yoke forward to "unload" the wing.  Is it a logical corollary of your answer that an instant sideslip would result, due to the resulting sink rate?  I.e. an immediate change in the direction of the "relative wind"?  Causing the yaw string (if present) to swing skyward, and the slip-skid ball to fall toward the earthward end of the glass tube?  Have you ever actually tried this maneuver?  I have.

@quiet flyer. Resulting sideslip due to loss of lift is correct.  However, the issue here is NOT starting from a banked turn, it's rolling into one with a dihedralled wing.  And, even with no dihedral, the loss of VERTICAL lift will cause a plane to sink.  Many answers focus on the SIDE slip, I am focusing on the DROP.  Please review your comment.

But are you suggesting that the "drop" causes a sideways component in the relative wind, in the aircraft's reference frame?  If so, see my comment above.  How is a drop due to rolling into a turn different from a drop due to shoving the stick forward while banked?  Sure, rolling into a turn will typically cause some sideslip due to adverse yaw and yaw rotational inertia, but will this sideslip be any more pronounced if we allow the plane to "drop" as it rolls, than if we pull the stick aft as needed to maintain altitude?

Pulling the stick "aft" to maintain altitude will eliminate the drop and increase the side force.  "Shoving" the stick forward could even create negative Gs!  BUT BOTH ARE PILOT INPUTS, the question seems to be about dihedral stability, correcting itself from an unplanned upset such as turbulence. Dihedral increases roll stability, starting with paper airplanes on up.  I am suggesting a drop helps right the plane simply because one wing is sticking out to the side more than the other.

@quiet flyer so the UPPER wing may have a LOWER angle of attack as well (it is pulling towards the side). This might be akin to the "twisting" airflow some talk about.

Dihedral generates a stabilizing roll torque due to the difference in angle-of-attack experienced by the left and right wings during a sideslip.
Furthermore, it's important to note that sideslip cannot be explained simply by noting that when an aircraft is banked, the tilted lift vector contains a sideways component, or that "from the point of view of the aircraft, lift is still acting in the plane of symmetry, but gravity does not and will cause it to sideslip", as is sometimes stated. (For example, we find something close to this in Martin Simons' well-known book "Model Aircraft Aerodynamics".)  Those are essentially Aristotelian concepts rather than Newtonian concepts. A continuous unbalanced sideways force component causes a turn, not a sideslip. Force causes acceleration, not steady sideways motion, and turning is a curvature in the flight path which is a form of acceleration.
Rather, sideslip is a result of not being pointed the same direction you are actually going. The reason that banking tends to cause sideslip has to do with the "curving" nature of the relative wind in a turn. Since the aircraft is rotating as well as translating, different parts of the aircraft are moving through the airmass in different directions at any given instant, which means if we map out the relative wind felt by various parts of the aircraft at any given instant, we get curved lines, not straight lines. Even if the vertical fin were perfectly streamlined to the flow at any given instant, more forward parts of the aircraft-- including the wing-- would be experiencing some sideslip. This effect is especially pronounced in aircraft with low "scale speeds"-- i.e. forward airspeed divided by fuselage length.
Yaw rotational inertia can also play a role in promoting sideslip immediately after an increase in bank angle, but this is probably a minor effect.
There is one other nuance to be pointed out that is probably a only very minor effect in most cases. Imagine an aircraft with zero dihedral flying at 10 degrees of angle-of-attack. Imagine that the aircraft abruptly rolls 90 degrees and the rolling motion is about the aircraft's lateral axis, not about the airspeed vector. The angle-of-attack will be converted to sideslip-- the aircraft will end up with 10 degrees of sideslip and no angle-of-attack. Now if we add dihedral, we'll see we end up with a roll torque. However this dynamic is probably trivial in normal roll stability dynamics which involve low rates of roll, allowing the aircraft's inherent pitch stability dynamics to maintain a constant average angle-of-attack, and allowing the aircraft's inherent "weathervane" stability to oppose sideslip, so that angle-of-attack does not end up being converted into sideslip simply by virtue of the rolling motion.

Outside links discussing "airflow curvature" effect should be added to this answer at some point.

This is a very exaggerated diagram of a fuselage with dihedral wings.
When the plane is flying normally (top), both wings produce the same lift vectors.
When the airplane is disturbed in the roll axis, and one wing goes higher than the other (bottom), the vertical lift vectors are different, with the "down" wing producing more vertical lift than the "up" wing. This increased vertical lift on the down wing and decreased vertical lift on the up wing, pushes the down wing up, and helps right the airplane.
Note: everything in this diagram is schematic and is not meant to indicate any specific mathematical or physics laws or formulas.

Note that in the second image, while the vertical is smaller, the horizontal, which is now above the center of gravity, would actually contribute to more bank, and possibly even overpower... Is this the cause for overbanking tendencies in steep turns?

yes, and its a good question that should be asked separately.

There is no rolling moment if the lift intensity is the same measured perpendicularly to the surfaces.

I'm not sure if your explanation is correct, as it does not include a sideslip component. As I understand it, both vectors remain the same in relation to the aircraft (thus no roll moment) unless a sideslip is involved.

This is an oft repeated fallacy. People think that gravity is something special and lift is only measured in relation to the ground. That is false reasoning. The lift generated perpendicular to the wings are the same therefore there is no net torque to correct the bank. If we add sideslip however the higher wing would have less lift due to lower AOA. Note that if the plane does not initially have any sideslip the higher wing will contribute a net side force that will create a sideslip - so yes, even without sideslip dihedral will self-correct because it will self-create the required sideslip.

@slebetman: Thank you for pointing this out. Just one nitpick: Your last sentence could be misunderstood that dihedral produces sideslip. The sideslip does not require dihedral - a roll angle will do it already, regardless of dihedral. The dihedral is needed to produce rolling from sideslip.


text:
Can I fly over Schengen zone without visa?
I don't have a Schengen visa. Am I eligible to fly over any Schengen country without landing there? Of course I mean that I take off from a non-Schengen country, and land in a non-Schengen zone as well.
Moreover, can I land somewhere in Schengen zone? For example, one touch-n-go in Schengen zone airport, and then fly back.
I consider that I fly an EASA-reg aircraft with an EASA pilot license.

As a clarification, you are not intended to fly in commercial aircraft but command your own aircraft, is that right?

Yep, just non-profit flight for fun in limits of my time building.

If you don't get a good answer here you might try travel.SE; they have a lot of questions about Schengen and other visa situations. Some countries do have flight crew visas, but I suspect that they're only available to professionals. Otherwise, I think it's likely the same rules will apply to you that would apply to anyone else flying commercially, but I really don't know for sure.

A visa is a permit to ask for permission to enter into a country by crossing its borders. Since you are not entering the country; but rather overflying it - you only need to worry about any requirements for your destination.
Now, if you are doing a technical stop, and you don't leave your aircraft - then you don't need a visa. This is true for normal passengers on commercial flights as well.
If you need to leave the aircraft, but not leave the sterile area of the airport - then depending on your nationality you may need a special crew visa (this is different than the normal visa you would get as a passenger).
For crew visas, there are no uniform rules. Each country is free to set their own permissions and requirements so you'll need to contact the embassy of the country you wish to stop in for information.
God forbid you face an emergency and have to land at a country and you don't have or don't know the visa requirements - there are provisions for such cases. Emergency permission can be provided to cross borders.
In all cases, make sure you carry a passport that is valid for at least 6 months after your return date.

Try to locate any nearby flight school, they will have experience with these topics.
Or you can contact your country's aviation authority.


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Will flying cars fall under aviation regulations?
As science and engineering keep inventing new technologies like flying cars http://www.iflscience.com/technology/are-flying-cars-finally-becoming-reality, air space may become heavily overcrowded. Will flying cars be considered "aviation" or are there (will there be) some rules like flying with particular altitude will be considered as aviation? (As the concept is becoming reality soon or later it has to be decided.)

The idea of a Flying car is not new.  Molt Taylor designed & built one back in the 1940s

Flying cars will need to be regulated by both the FAA and the DOT as per current laws here in the US. For what its worth flying cars are really more like road capable airplanes. When the car is airborne it will be subject to the regulations set fourth by the FAA for the airspaces it passes through and maneuvers it makes. When the car is on the road it will be subject to vehicular laws that any other car would see. That being said there is room for change here and who knows what rules may be passed in the future. There is also some grey area around things like landing in a parking lot, folding up your wings and driving away as well as the reverse case.
The rules that currently govern aviation are more than capable of handling flying cars, even if they start taking off from peoples driveways. The larger issue is licensing the pilots. A drivers license is pretty easy to come by here in the states while a PPL or sport pilots license takes quite a bit of time. Everyone that currently would want a flying car would need both a drivers license and a pilots license of some form.
As far as I know the FAA makes the rules for any and all altitudes. While some airspaces (class G) may be unregulated they are still considered from the ground up. There is no minimum altitude at which FAA regulations don't apply and its far from a free for all in the skys the way it is on the roads in a manner of speaking.
Flying cars could potentially cause an increase in air traffic however the advantage of a plane (over driving) is generally speed. Until someone can build a car that can do 80MPH consistently on the road and a formidable 130Kts (and thats the slow end of planes) through the air the use case is pretty small.
One of the biggest preventers in the whole flying car situation is the engine its self. Car engines fit quite a different role than aircraft engines. The similarities end basically at the fact they are both piston engines. Some car engines have been put in planes (Mooney/Porsche PFM 3200) and in the end they are generally not great planes. You can find a full discussion on this here. You also need to keep in mind that anyone who will be fixing these vehicles will need to be an A&P licensed mechanic.
There are a few companies with some cool animations of future products and even a few test rigs that have been built but to date the engineering is just not really there. Chances are it will be some time before flying cars are even on the road let alone creating major air traffic issues. For the 279,000 a Terrafugia will cost you, you could buy a Used Piper Arrow (in great shape) and a Porsche and still have 79,000 left over for a hanger to keep them in...

"A drivers license is pretty easy to come buy here" Freudian slip?

Theoretically a small enough flying car might be considered an ultralight.

@Dave: This company has already a couple of prototypes flying. The time may be closer than you think.

There is still a lot they need to work through

@BogdanWilli Terrafugia has had prototypes flying for several years, but they're still perpetually 18-24 months from first delivery.

At least one company envisions a self-flying flying car.


text:
What education is needed to become a civil pilot?
I'm from Croatia and I'm intersted in becoming a pilot, but however, I'm not going to the college deisgned for that (I'm studying IT, not aeronautics).
Nevertheless, I contacted Croatia Airlines and they told me that I needn't have an aeronautics college degree, but I do need these qualifications to apply for the First Officer (Co-pilot) position:

hold a valid CPL (A)
hold a valid multi-engine instrument rating (airplane) (ME-IR(A))
successfuly completed a Multi Crew Coordination (MCC) Course
hold a Category 1 Medical Certificate
hold a valid Associate Degree
hold at least English Proficiency Level 4
hold a certificate of passed ATPL (A) theoretical knowledge examinations according FCL.515
be minimum of 21 years of age
total flight time:

Ab-initio pilots: at least 250 hours total time, to include 100 hours as pilot-in-command of airplanes
Pilots with valid type rating: a minimum of 500 hours on respective type

So, I have a few questions.

Does someone know where I can get my licences for being an civil pilot in Croatia?
About theoretical knowledge (physics, mathematics):

Could I watch MIT OpenCourseware on that (and if I do, should I watch this or this?
I stumbled upon Flying Academy website (can't post the link because I'm new here) and it says "Sufficient level of knowledge of Mathematics and Physics".
What is sufficient and what would I have to learn?

I know I have a lot of questions, but I would really like to become a pilot one day and I believe I am self-disciplined enough to learn on my own. Can someone show me the way?

OK, and what about the "Sufficient level of knowledge of Mathematics and Physics"? I don't have Physics on my college, so I need to teach myself.

Both of those MIT courses cover very interesting material and are worth sitting through, but they are well beyond what you will ever need to know as a pilot. If you can understand the material in there the understanding of mathematics and physics you have VASTLY exceeds the requirements for any pilot certificate you could ever want to earn. :)

Did you check this page of the Croatian Civil Aviation Agency?   http://www.ccaa.hr/english/faq_82/                                                                 I suspect if you contact the Training and licensing Department they can walk you through the procedures http://www.ccaa.hr/english/contacts_81/

I did contact CCAA, but they redirected me to The College of Traffic Sciences. I'll try contacting Training and licensing Department directly.

When you say "I'm from Croatia", I take that to mean that English is not your native tongue. Given that, and reading your question, I doubt you'll have any issue with the English proficiency. You may have an accent that would identify you as Croatian, but your command of the language is significantly better than many Americans I've come across.

First, does someone know where I can get my licences for being an civil pilot in Croatia?

I'm afraid nobody here can help you with that: You will need to find a flight instructor or flight school in your area. (Google can probably help you locate candidate schools, and we have some general advice on selecting a school and selecting an instructor that might help you narrow down your choices.)

Second, about theoretical knowledge (physics, mathematics), could I watch MIT OpenCourseware on that (and if I do, should I watch this or this? I stumbled upon Flying Academy webiste (can't post the link because I'm new here) and it says "Sufficient level of knowledge of Mathematics and Physics".
What is sufficient and what would I have to learn?

To begin flight training you don't need to know anything about math or physics: Your initial training will be about manipulating the controls of an aircraft to make it do what you want it to do, and for the moment you don't care how or why it works, you just need to learn the physical technique of controlling an airplane.
At some point in your training you will learn the physics of flight - this is generally part of "Ground School" but your flight instructor may introduce the concepts to you as you approach lessons where they will be relevant.
A basic understanding of the laws of motion and air pressure will be helpful, but everything you need to know can be found in the various FAA handbooks (the Pilot's Handbook of Aeronautical Knowledge, the Aeronautical Information Manual, and the Airplane Flying Handbook are good starting places - regulations will probably differ in Croatia, but the basics of flight will be the same, and are explained in fairly simple language in those books).
You will also need to be able to work basic flight planning calculations as you advance in your training, which means you will need some basic mathematical knowledge: The ability to add, subtract, multiply, divide, and do simple algebra will cover nearly everything you need to do as a pilot, and higher math is generally not necessary unless you start getting into the Why of aerodynamic theory.

Thank you so much man! :) I'll first go through these handbooks and if I have the time, then I'll watch MIT stuff (because, as I said, I am currently attending another college, so it's not like I have all day for learning aeronautics).


text:
Was the runway upgrade at Mataveri Airport on Easter Island really related to the Lee Correy novel "Shuttle Down"?
This answer to the question Could the Space Shuttle have landed on any long runway other than those specially reinforced at Kennedy (TTS), and Edwards (EDW)? says:

The Mataveri Airport on Easter Island was a planned abort site for the Space Shuttle. Since the Space Shuttle has no means of propulsion, you might want to have a fairly tight mesh of potential landing sites in event of an emergency.
As a nice side-effect, the long runway allowed for larger passenger aircraft to service the island, which boosted tourism. A nice win-win situation.

What caught my eye is the comment:

The runway improvement happened only after the problem of an unprepared emergency landing there occurred... in a novel. But then none of the Vandenberg launches for which it would have been a launch abort site ever ultimately happened.

followed by this comment:

He's probably talking about Shuttle Down by Lee Correy. https://en.wikipedia.org/wiki/Shuttle_Down

Question: Is this timing factually correct? If so, was this coincidental, or is there in fact some causal aspect to the relationship?

The timing is correct. Shuttle Down was published in 1980 and the agreement with Chile to pay for the runway extension wasn’t until 1985 with the extension coming into use in 1987.

I've left word of this question in Space SE looking for additional information from NASA. There can certainly be factual information that can address this question, let's wait a bit to see before labeling the question "primarily opinion-based".

As much as I enjoyed reading the novel after reading the Wikipedia article about Mataveri Airport I am somewhat disappointed by my answer. The novel was published in 1980 and the official agreement between the United States and Chile was not signed until 1985 there is circumstantial evidence that the novel did not play a causal role.
In Glynn S. Lunney's Oral History from NASA's Oral History Project. Link to Full Text It appears that from very early on in the Air Force's involvement with the Shuttle Project that Easter Island was identified as a possible abort landing site. They didn't like it because of the short runway but they thought about it. Because this is an oral history it is hard to pin down exactly when these thoughts were happening but the context makes it look like it was quite early.
Naturally all of the news articles from 1984-1987 about the extension I found never mention the novel. Nor does the official text of the Agreement.
It was a fun little novel though. Which strangely enough foresaw most of the logistical problems that would arise from having a NASA retrieval crew on Easter Island. Especially the water and sanitation limits.
Having kept looking for a bit I found an interesting declassified memo from 1966! The Air Force has been considered their own manned space flight program launching from the Western Test Range heading south and using Easter Island as a possible abort landing sight. Another memo from 1967 says it got so far as actual discussions with the Chilean government. Even though these documents were classified it is clear that the idea of using Easter Island as an emergency landing site did not come from the novel.

+1 Thank you for looking into this! Now I'm intrigued; I'll try to find a copy to read myself. I'm curious; were you already familliar with the situation somewhat and had read the news articles, or is that research you've done just now in order to answer the question?

Sounds like people have it backward. The possibility of the Easter Island backup probably inspired the novel

I live on Easter Island and most people here are familiar with this story. The novel DID pique NASA's interest in extending the runway here to accommodate the especially modified 747 that carries the shuttle. Up until the publication of the novel they had not considered the problem. In the mid 1960's an agreement with Chile enabled the US to set up a tracking station on Easter Island for the surveillance of artificial earth satellites. Some hundred North American military men were stationed on the island between 1967 and 1971. They left right before marxist president Salvador Allende was elected into office, foreseeing conflict.
The novel was first published in four instalments in a science fiction magazine between 1980-1981. The matter was being discussed for quite some time before the news officially broke out on June 30, 1985, that the then-military government had approved NASA's request to extend the airstrip, which they completed in 1987. It was also agreed to periodically re-pavement the runway, which they did in 1997 and most recently in 2011. NASA used to be in charge of repavementing of the airstrip, but not anymore as far as I know.
In April 1967, LAN airlines introduced flights from Santiago to Easter Island, and on January 16, 1968, the Santiago-Easter Island flight was extended to Tahiti. In the 1970s the plane that flew to the island was a weekly B-707, before it had been a monthly DC-6B aircraft.  The runway had originally been extended and paved for use as a U.S. base. In 1993, with the new wider and longer runway, flight service was extended to twice-weekly replacing the Boeing 707 with a Boeing 767-200ER. In more recent times the island has seen the Boeing 767-300ER, Airbus A340, and the Boeing Dreamliner 787, receiving as many as three flights from Santiago in one day.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How did this air force plane likely get into the eye of Hurricane Florence?
The annotation for this CNN video says

Air Force plane flies into Hurricane Florence
Watch as a US Air Force plane flies into the eye of Hurricane Florence to collect weather data for the National Hurricane Center. Source: CNN

But I can't find any information on what kind of plane this is nor how it safely got into the eye in order to record this.
Would they generally fly through the storm at this altitude, or do they fly above it to reach the eye, then "drop down" into the eye?
The video is also viewable here where the footage is between 00:24 and 00:40.

related: https://aviation.stackexchange.com/q/43587/1467 (disclaimer: my question)

@ymb1 If the answer for the NOAA's P3 Orion and the answer for the Air Force's plane in this question is identical, then yes possible. But of the answers are different because the planes are different, then perhaps not. Per this answer this might be a C-130, but I have no idea.

@ymb1 this Air Force craft certainly looks more like a P-3 than a C-130, I'll vote to close as well. https://www.bbc.com/news/av/world-us-canada-45506952/hurricane-florence-hunters-enter-storm

They fly straight through, as part of their mission to collect meteorological data about the storm, used for forecasting (NOAA's G-IV fleet flies the periphery of storms to collect data used to help predict the path of hurricanes). A typical path:

We'd begin by making a "figure 4," with the vertical and the horizontal legs crossing at the center of the eye.

This image shows the flight path taken during one observation of Hurricane Patricia in 2015 (from this blog post).
Wikipedia has information about "hurricane hunter" operations, and Google produces many, many results about how these flights work, including videos (even an entire documentary series) and interviews with the crews that fly them. Here's a recent news story featuring an interview with an Aerial Reconnaissance Weather Officer who flew into Hurricane Florence.
The US Air Force's 53rd Weather Reconnaissance Squadron flies the WC-130 (a C-130 variant equipped with meteorological observation equipment and dropsonde deployment capability). Additionally, the National Oceanic and Atmospheric Administration flies a fleet of two WP-3D Orion aircraft (modified P-3 Orions) and one Gulfstream IV, which flies around the periphery of storms to collect weather data.
You can plot their exact flight paths on Google Earth, if you're so inclined.
The Hurricane Hunter Association's site also addresses this question in their FAQ:

Do you fly over the top of the hurricane? NO!!
The tops of a big hurricane can be over 50,000 feet high, and our planes could never get
  up there (they can only go up to 30,000 feet). Besides, the weather
  we're interested in is down at the bottom of the storm, where it will
  affect the coastline it hits. For this reason, we fly in as low as
  possible and still be safe. This altitude can be anywhere from 1,000
  feet to 10,000 feet.

They also include an image of their typical "alpha" flight path, typically making four passes through the center of the storm.

I see, thanks! So the images shown by CNN, while beauitiful, are secondary to what the National Hurricane Center and the Air Force plane are there to do. Also, thank you for the Google Earth link, I will look into that soon!

Only 53 people have died doing this since 1943... can't believe it is so safe...

for more info on the actual planes used - https://en.wikipedia.org/wiki/Lockheed_WP-3D_Orion

The US Air Force 53rd Weather Reconnaissance Squadron's main task is to gather data about storms. They fly C-130s into and around storms including hurricanes.
Anilv

Not a very complete answer

@Cloud at least it answers the "what kind of plane" part of the question, and provides the Air Force unit that flies them, neither of which is in the other answer.

@fooot, except there are three kinds of planes (WP-3D Orion, C-130 and Gulfstream IV) and the Orion is the one that does the most daring low altitude penetration (and carries the biggest radar).

https://www.bbc.com/news/av/world-us-canada-45506952/hurricane-florence-hunters-enter-storm


text:
Are there little seat belts or other restraints for the organ-containing coolers kept in cockpits?
The NPR podcast A Surgeon Reflects On Death, Life And The 'Incredible Gift' Of Organ Transplant features Dr. Joshua Mezrich a surgeon who flies to other hospitals to retrieve organs for transplant discussing his book When Death Becomes Life.
In the beginning of the interview he says (my transcription effort):

There’s lots of different ways different centers do it. At our center we have some pilots who fly for the state who are on call for us, and typically we fly in a Pilatus, which is a single engine turboprop,
It is true that organs sometimes get sent on commercial planes; kidneys in particular, so if you ever see a cooler in between the pilots when you board it’s typically a kidney.

Are there little seat belts or other restraints for the organ-containing coolers kept in cockpits of commercial aircraft? Or are they just placed on the floor?

I couldn't find a stowage or luggage tag, so I chose cargo.

"between the pilots" depends on the aircraft. On larger commercial aircraft and even some fairly small planes the area between the seats is occupied by the FMS and throttle units and there really isn't anywhere to put a cooler as seen here:

(source)
A lot of aircraft (bigger than the PC-12 mentioned) have jump seats in the cockpit. If unoccupied these seats have a set of restraints that could theoretically hold a cooler depending on size.
You can find the legality of putting stuff on the floor in the cockpit in answer to this question.
For short distances organs move in helicopters and for longer distances they may move in a private jet presumable in the back with a courier. I would not jump to the conclusion that coolers in the cockpit are organs. Ive seen a few organs loaded into lear 35's at my local airfield.

For the record, if you ever see a cooler in my cockpit its more than likely a ham and cheese sandwich.

What, not a kidney and cheese sandwich?  ;-P

@Sean there was that one time, but thankfully the archer has a small pilot relief window....

@Dave Ha! And here I thought that was an air vent...

Given the way the air tends to come into the cockpit via that hole, it pains me to imagine the fluid dynamics involved in attempting to jettison a former lunch by way of that vent...

@Tim my advise is to use your hands as a kind of directional funnel. You are generally best to ask from some paper towels on UNICOM before landing...


text:
Which airports have the highest fuel upload?
Which airports consume the most fuel for aircraft refueling, and how much fuel do they use?   I was able to find that "Heathrow uses about 20m litres of fuel a day", but it isn't easy to find figures for other airports.

The best data I could find is in this paper about biofuels, which has data for US airports in 2014. Based on my reading of the chart on page 14 and some conversion:
Airport  Millions of barrels per year
KLAX     48.6
KJFK     43.5
KATL     30.8
KORD     30.5
KSFO     28.3
KMIA     26.0
KDFW     25.4
PANC     19.0

Comparing this to the top US airports in 2013, it is interesting to note that LAX and JFK use significantly more fuel than KATL, despite passenger traffic figures ranked the other way. Also notable is Anchorage showing up here right after DFW, while MIA and ANC are the only ones not in the top 10 by passengers, showing up at 11th and 58th, respectively.
Figures for other countries have been harder to find. This article from 2004 estimates the Dubai International usage at 24.2 million barrels that year, which has certainly grown since then. The 2012-2013 environmental report from Emirates Group lists their consumption at 73.9 million barrels, and half of this figure would be in line with the other numbers available.
I found a similar figure for Heathrow, listing it at 20-25 million liters per day, depending on season, which gives a range of 61.2 to 76.5 million barrels per year, well ahead of the US airports.
Becoming even fuzzier, the pipeline to Narita Airport in Tokyo transported 130 billion liters in its first 30 years of operation, which averages out to 36.3 million barrels per year.

Anchorage is a major refueling stop for freight, being toward the middle of the great circle route for much of North America to much of East Asia.

LAX and JFK both have massive amounts of long-haul traffic, much more than Atlanta. Atlanta, on the other hand, has more domestic passengers than JFK and LAX put together. While MIA is not in the top 10 by total passengers, it's number 2 by international passengers, with almost half of its passenger traffic being international, so that's why it makes the list. ANC makes the list primarily for the reason digitgopher mentioned, though the fact that much of Alaska is accessible only by air also adds to this.

fooot - thank-you very much.   It is good to have complete U.S. numbers, and the Dubai report is a good find as this airport must be a candidate for number one.

Here's a claim of 12.8 million liters per day for Narita: Jet fuel consumption in Japan

I found a few sources of data that is close but not specifically what you are looking for (Im going to keep looking)
Here is the total Jet fuel consumption reported by the DOT (you can filter by airline/carrier)
Here is the Jet fuel consumption by state in the USA
Here is an interesting report on fuel storage at airports.
Im sure the number vary over time as well as seasonly depending on where in the world you are talking about. On one hand you can argue that the distance/weight comparison of airports may be a useful metric. If we assume planes are least efficient and require the most fuel when flying far and heavy the airport with the greatest departing mass/distance value could shed some light on the number you are looking for (I have no idea how to figure out that number for the record).
Keep in mind that there is a growing number of planes that are running on Jet A1. A solid chunk of the smaller charter fleet that runs Turbo Props runs on Jet A1 as well as planes like the Piper Meridian and other similar turbo props sneaking their way into the GA market. To round it out diesel GA planes run on Jet-A1 and things like the Diamond-DA42 are making an impact on the GA market and increasing Jet-A1 consumption even if just marginally. That all being said just because a state has a single large or even mega sized airport other states with lots of GA or small charter traffic out of little fields may be able to keep up.

Thanks for your answer so far!   I actually started out doing the opposite.  I wondered at which airports the highest number of passenger miles terminate, and fuel seemed like a reasonable proxy for that number.  But it's quite an interesting topic in itself.    I'm finding the per-state numbers hard to interpret - Georgia is listed as consuming just 3,833 thousand barrels per year, despite the presence of ATL.

Easiest way is just to look at the busiest airports in the world, they have the most planes flying in and out, therefore, they have to fuel more.

That's probably close, but not necessarily an accurate metric: Airlines will tanker fuel if it's substantially cheaper at another airport (i.e. "If the cost of fuel at the busy airport exceeds the cost of hauling the extra weight from the less busy field the plane was at previously").

Another factor would be the type of traffic. An airport with a lot of international traffic on large planes may use more fuel. For example, even if Atlanta is the busiest in the world, somewhere like Dubai might use more fuel.

@fooot Yeah, the 30-minute hops from Atlanta to Nashville don't use quite the same amount of fuel as, say, Atlanta to Incheon. While Atlanta has an absolutely massive amount of domestic traffic (IIRC, its domestic passenger throughput alone is higher than the total passenger throughput of any other airport in the world,) it doesn't have as much long-haul traffic as a lot of other airports. On the other hand, I'm not sure how fuel consumption per passenger compares between lots of small and medium-sized aircraft vs. fewer large aircraft.

You also have to consider that long haul flights are more fuel efficient.  The aircraft generally fly higher and can take advantage of the jet stream.